DOPPLER RADAR STUDIES OF STORM MOTION.
Final rept. 1 Jan 67-31 Dec 69,
ALLIED RESEARCH ASSOCIATES INC CONCORD MASS
Pagination or Media Count:
Analyses of Doppler radar measurements were made in different storms. In the storm of 26 Jun 1968, periods of heavy rain were associated with the passage of short-wave troughs at different levels in the atmosphere. There was a marked change in the wind field during a 15-minute period in the snowstorm of 7 February 1967. Discontinuities in the VAD pattern were interpreted as part of a sloping surface similar to a quasi-stationary front. The snowstorm of 29 February-1 ARCH SHOWED INCREASING STRONG NE winds at low levels increasing with time as the storm center approached. At upper levels above 5 km the reverse situation occurred strong southerly winds decreasing markedly with time as the upper level low approached. In a thunderstorm on 7 Jun 1967, vertically pointing Doppler radar revealed the existence of a large tower extending above 12 km with upward velocities of 9 to 11 km, probably signifying updrafts of 10 to 15 msec. Deviation of storm motion from that of the environmental winds is due primarily to new cell growh on one side, dissipation on the other. The Magnus effect may play a role only during the later stages of the storm. Formulae for propagation rate and the motion of storm lines are derived, assuming constant line length and cell development along the line. Author